Floods and Fires
I think as John says, some of them don't really bother with the carpet cleaning side of the business.
I'm led to believe that part of the franchaise agreement is that they have to purchase £200 worth of these two part carpet cleaning chemicals each month from the parent company, regardless as to whether they use them or not. This cost only equates to about 6 or 7 single uses of the system @ £30 a fill.
You need to be charging very top dollar to make any margin on those overheads.